Chapter 5 - Ground Crew Supplement

Representative Aircraft Surfaces

Note:  Transport Canada no longer maintains a list of approved representative aircraft surfaces.

115.  Air carriers that have established a program in accordance with GOFR 622.11 may have representative aircraft surfaces designated and approved for their aircraft. Representative surfaces that can be clearly observed by flight crew from inside the aircraft may be suitable for judging whether or not critical surfaces are contaminated. Guidelines for the approval of representative surfaces have been developed.

116.  Many operators have painted a portion of the representative surface in a darker colour to aid in the visual detection of contamination. Some have designated representative surfaces on both sides of the aircraft in the event that, due to strong wind during taxi, one side of the aircraft becomes contaminated before the other.

117.  Research has indicated that fluid failure occurs last at the mid chord sections of wings. Therefore, whether painted or not, areas located at mid chord sections of wings and previously used for checking fluid conditions are not suitable for evaluating fluid failure and should no longer be used exclusively as representative surfaces.

118.  Pre-take-off contamination inspections should be concentrated on the leading edge in conjunction with the trailing edge of the wing. Dependent upon aircraft configuration, wing spoilers may also be used to provide an indication of fluid condition.

119.  In addition to the representative surface, other aircraft critical surfaces which are visible from inside the aircraft should be inspected for contamination whenever possible.

120.  While not recommended, if ground operations are to be conducted in freezing precipitation conditions, TC strongly recommends the use of Type II, III or IV anti-icing fluids (in accordance with the aircraft manufacturer's instructions) in order to take advantage of their superior protection characteristics.

The decision to take off following the pre-take-off inspection is the responsibility of the PIC.